1. Field
Embodiments of the present invention relate to a photosensitive resin composition including a photoacid generator, a method of forming an organic layer using (utilizing) the photosensitive resin composition, and a display device including the organic layer.
2. Description of the Related Art
In a display device employing a thin film transistor (TFT), a protective layer is used (utilized) to protect and insulate the TFT. An inorganic protective layer such as silicon nitride (SiNx) or silicone oxide (SiOx) is mainly used (utilized) as the protective layer. The inorganic protective layer is formed by vacuum deposition, but vacuum deposition is a costly and time-consuming process. Further, the inorganic protective layer has a high dielectric constant, and thus there are limitations to improvement in the aperture ratio of a display device. In order to overcome the limitations, research is being carried out to use (utilize) an organic layer, which has a low permittivity (permeability) and may be formed by a coating method using (utilizing) a liquid composition, as an insulating layer.
In the case where the organic layer is characterized by having photosensitivity in particular, a fine pattern may be formed on the organic layer without an additional process. A photosensitive resin, which participates in a photoreaction to change its solubility in a specific solvent, is used (utilized) to form such an organic layer pattern. A chemically amplified resist may be used (utilized) as the photosensitive resin in which solubility is changed by a photoreaction. The chemically amplified resist contains an acid-labile resin and a photoacid generator, and an acid (H+) is produced from the photoacid generator of a light-exposed area (in an area exposed to light), and the acid amplifies a chemical reaction of the acid-labile resin.
The chemically amplified resist needs activation energy for the chemical reaction of the acid-labile resin, and the activation energy is generally given (provided) by heat. Therefore, a post exposure bake should be further performed to heat the organic layer after exposure (to light) in order to form a pattern using (utilizing) the chemically amplified resist. A separate baking unit is required for the post exposure bake.
Meanwhile, demand for a digital exposure apparatus as an exposure device is increasing. The digital exposure apparatus controls a plurality of spot beams to be on or off to perform selective exposure (of a photosensitive material) to light. In the case of using (utilizing) the spot beams, the selective exposure may be performed without a separate pattern mask. In the case where a pattern is formed on only a particular partial area, such as a contact hole of a display device, the pattern may be simply formed by using (utilizing) a positive photosensitive material and the digital exposure apparatus. However, in the event that ultraviolet light with a short wavelength, e.g., ultraviolet light with a wavelength of 365 nm, is used (utilized) in the digital exposure apparatus, a metal or mirror part of the digital exposure apparatus may be easily damaged.